Method and system of managing voice call and IP media sessions in a wireless network environment

ABSTRACT

A network entity and an operating method thereof in a communication system are provided. The method includes establishing a first connection with a user equipment (UE) using a first access technology; receiving, from the UE, via the first connection, capability information on communication with a second cell using a second access technology different from the first access technology; transmitting a first signal to the UE via the first connection; and transmitting, to the UE, via the first connection, configuration information related to the second cell for establishing a second connection between the UE and the second cell. The first cell and the second cell are simultaneously active for the UE.

PRIORITY

This application is a Continuation Application of U.S. patentapplication Ser. No. 16/725,404, filed in the U.S. Patent and TrademarkOffice (USPTO) on Dec. 23, 2019, which is a Continuation Application ofU.S. patent application Ser. No. 16/199,772, filed in the USPTO on Nov.26, 2018, and issued as U.S. Pat. No. 10,517,028 on Dec. 24, 2019, whichis a Continuation Application of U.S. patent application Ser. No.15/018,084, filed in the USPTO on Feb. 8, 2016, and issued as U.S. Pat.No. 10,142,902 on Nov. 27, 2018, which is a Continuation Application ofU.S. patent application Ser. No. 13/697,676, filed in the USPTO on Nov.13, 2012, and issued as U.S. Pat. No. 9,258,840 on Feb. 9, 2016, whichis a National Phase Entry of PCT International Application No.PCT/KR2011/003572, which was filed on May 13, 2011, and claims priorityto Indian Patent Application Serial No. 1361/CHE/2010, which was filedin the Indian Intellectual Property Office on May 13, 2010, the entirecontent of each of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates generally to wireless communication, andmore particularly, to handling voice calls and Internet Protocol (IP)media sessions in a wireless network environment.

2. Description of the Related Art

Generic Access Network (GAN) is a telecommunication system that extendsmobile voice, data, and IP Multimedia Subsystem/Session InitiationProtocol (IMS/SIP) applications over IP networks. In GAN, a UserEquipment (UE), upon detecting a wireless Local Area Network (LAN)(e.g., a GAN cell), establishes a secure IP connection through a gatewayto a server called a GAN controller on the cellular network. On thecellular network, the UE communicates over the air with the base stationto servers in the core network of the carrier. An advantageous featureof a GAN system is the ability of the UE to migrate from the IP tocellular coverage. Thus, when the UE moves from a Global System forMobile Communications (GSM) network to an 802.11 network, it appears tothe UE as if the UE is communicating with a different base station.

Today, with operators hosting multiple services and other services beinghosted by third parties on the Internet, operators prefer to selectivelyhandover certain IP media sessions to the GAN cell when available.

However, the GAN system does not support simultaneous access acrossdifferent Radio Access Technologies (RATs) like GSM Enhanced Data Ratesfor GSM Evolution (EDGE) Radio Access Network (GERAN) and GAN. So, whena GAN cell is detected, the UE attaches to the GAN cell and voice and IPmedia sessions of the UE are transferred to the GAN. Currently, there isno method for selectively offloading IP media data streams to the GANwhile maintaining an ongoing voice call (e.g., circuit switched networkcalls) on the existing GERAN/Universal Terrestrial Radio Access Network(UTRAN).

SUMMARY OF THE INVENTION

Accordingly, the present invention has been designed to address theabove and other problems occurring in the prior art, and provide atleast the advantages described below. Accordingly, an aspect of thepresent invention provides a method and system for managing voice calland IP media sessions in a wireless communication environment.

According to an aspect of the present invention, a method is providedfor a network entity of a first cell in a communication system. Themethod includes establishing a first connection with a user equipment(UE) using a first access technology; receiving, from the UE, via thefirst connection, capability information on communication with a secondcell using a second access technology different from the first accesstechnology; transmitting a first signal to the UE via the firstconnection; and transmitting, to the UE, via the first connection,configuration information related to the second cell for establishing asecond connection between the UE and the second cell. The first cell andthe second cell are simultaneously active for the UE.

According to another aspect of the present invention, a network entityis provided for a first cell in a communication system. The networkentity includes a memory; and at least one processor coupled to thememory. The at least one processor is configured to establish a firstconnection with a user equipment (UE) using a first access technology,receive, from the UE, via the first connection, capability informationon communication with a second cell using a second access technologydifferent from the first access technology, transmit, to the UE, via thefirst connection, a first signal, and transmit, to the UE, via the firstconnection, configuration information related to the second cell forestablishing a second connection between the UE and the second cell. Thefirst cell and the second cell are simultaneously active for the UE.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the presentinvention will be more apparent from the following detailed descriptiontaken in conjunction with the accompanying drawings, in which:

FIG. 1 is a block diagram illustrating a wireless communication systemfor managing voice call and IP media sessions, according to anembodiment of the present invention;

FIG. 2 is a process flowchart illustrating a method of managing videocall and/or IP media sessions in a wireless communication environment,according to an embodiment of the present invention; and

FIG. 3 is a flow diagram illustrating a method of indicating decision toselectively offload IP media session to a GAN cell, according to anembodiment of the present invention.

The drawings described herein are for illustration purposes only and arenot intended to limit the scope of the present disclosure in any way.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE PRESENT INVENTION

Embodiments of the present invention are described in detail hereinafterwith reference to the accompanying drawings. In the followingdescription, the same drawing reference numerals may be used for thesame or similar elements even in different drawings. Additionally, adetailed description of known functions and configurations incorporatedherein may be omitted when such a description may obscure the subjectmatter of the present invention.

FIG. 1 is a block diagram illustrating a wireless communication systemfor managing voice call and IP media sessions, according to anembodiment of the present invention.

Referring to FIG. 1 , a wireless communication system 100 includes acore network 102, a GERAN/UTRAN cell 106 (also referred as first networkcell) associated with a preferred RAT, a GAN cell 108 (also referred assecond network cell) associated with a RAT of different type, and a UE110.

The core network 102 serves the UE 110 via the GERAN/UTRAN cell 106and/or the GAN cell 108. The GERAN/UTRAN cell 106 provides voice calland/or IP media service to the UE 110 when the UE 110 is attached to theGERAN/UTRAN cell 106. When the UE 110 is attached to the GAN cell 108,the GAN cell 108 provides data streams associated with the IP mediaservice from the core network 102.

In the present example according to an embodiment of the presentinvention, the UE 110 is registered with the GERAN/UTRAN cell 106 andthe GAN cell 108. A video call and IP media sessions are also ongoing onthe UE 110 and the core network 102 over the GERAN/UTRAN cell 106. Insuch a case, the video/IP media session handling module 104 determineswhether the UE 110 has selective IP media session offloadingcapabilities. According to an embodiment of the present invention, theUE 110 indicates its IP media session offloading capabilities to thecore network 102 when registering for video call/IP media services withthe core network 102.

If the UE 110 has offloading capabilities, the handling module 104selects at least one of the IP media sessions or its portions foroffloading to the GAN cell 108. The handling module 104 then routes datastreams associated with the selected IP media session(s) via the GANcell 108 while the remaining IP sessions and the voice call isprovisioned over the GERAN/UTRAN cell 106. This routing helps mitigatedata load on the GERAN/UTRAN cell 106. Certain embodiments of thepresent invention provide a mechanism for data splitting at an accessmode level to maintain multiple streams, where policy to send differentapplication data streams on different RATs is indicated to Logical LinkControl (LLC) entity. The LLC entity then maps the data streams from aparticular application to a particular LLC to access mode Service AccessPoint Identifier (SAPI). The policy information can then be passed tothe LLC from Sub-Network Dependent Convergence Protocol (SNDCP) layer. Aprocess of handling voice call/IP media session call according to anembodiment of the present invention is described in greater as followswith reference to FIG. 2 .

FIG. 2 is a process flowchart illustrating a method of managing videocall and/or IP media sessions in a wireless communication environment,according to an embodiment of the present invention.

Referring to FIG. 2 , in step 202, a cell is scanned in a preferred RAT,such as GERAN and UTRAN. At step 204, it is determined whether any cellis found in the preferred RAT during scanning. If no cell is found, thenat step 206, it is determined whether a maximum number scans areperformed. If the maximum number of scans is performed, then at step208, any cell of a given RAT is used for camping in an emergency mode.Otherwise, steps 202 and 204 are repeated.

If, at step 204, it is determined that a cell is found, then at step210, the UE 110 registers with the GERAN/UTRAN cell 106. Also, at step210, the UE 110 scans for a GAN cell in another RAT. This scan isperformed irrespective of whether the UE 110 has successfully registeredwith the GERAN/UTRAN cell 106. At step 212, it is determined any GANcell is found in another RAT during the scanning operation. If any GANcell is found, then at step 214, the UE 110 selectively registers withthe GAN cell 108. Otherwise, step 210 is repeated. During this process,the UE 110 stays attached to the GERAN/UTRAN cell 106 and simultaneouslylatches onto the GAN cell 108.

At step 216, it is determined whether video call and at least one IPmedia session are simultaneously ongoing on the UE 110 over theGERAN/UTRAN cell 106. If the voice call and at least one IP mediasession are not ongoing simultaneously, then at step 218, the UE 110detaches from the GERAN/UTRAN cell 106. If the voice call and at leastone IP media session are ongoing simultaneously, then at step 220, it isdetermined whether a voice call is ongoing over the GERAN/UTRAN cell106. If it is determined that the voice call is ongoing over theGERAN/UTRAN 106, then at step 222, the voice call is provisioned on theGERAN/UTRAN cell 106, and step 224 is performed.

At step 224, it is determined whether any of the IP media sessions to beoffloaded on the GAN cell 108. If the IP media sessions to be offloadedon the GAN cell 108, then at step 226, data streams of the at least oneIP media session are routed over the GAN cell 108. Otherwise, at step228, the ongoing IP media sessions are provisioned over the GERAN/UTRANcell 106. Thus, both the video call and IP media sessions areprovisioned simultaneously over the GERAN/UTRAN cell 106 and the GANcell 108, respectively, by selectively offloading at least one IP mediasession, or parts of at least one IP media session, to the GAN cell 108.To achieve this selective offloading, a Non-Access Stratum (NAS) entitymust identify two active cells simultaneously in a GAN/GERAN/UTRANnetwork and maintain two active states of the GERAN/UTRAN cell and theGAN cell. This identification involves signaling (e.g., RAU, measurementreports, etc.) for GAN and GERAN in SAPI-1 and defining a new SAN, andthus maintaining simultaneous active states of the GERAN/UTRAN cell andthe GAN cell.

In accordance with the above-described embodiments of the presentinvention, the core network 102 may send a paging message to the UE 110over the GERAN/UTRAN cell 106 or the GAN cell 108. If the paging messageis for a voice call connection, the GERAN/UTRAN cell 106 is used forprovisioning the voice call connection. If the paging message is for anIP media session, then the UE 110 responds with the paging responsebased on the intimation by the core network 102. In both of the abovecases, the core network 102 may choose to page the UE 110 in either ofthe cells 106 or 108 and specifies, in the page message, a cell throughwhich the UE 110 shall respond to the page message.

When uplink data must be transferred, the UE remains latched onto theGERAN/UTRAN cell 106 and the GAN cell 108, and then offloads the entireIP media session or a portion of the IP media session to the GAN cell orcontinues with the transmission of data over the GERAN/UTRAN cell 106based on order from the core network 102.

FIG. 3 is a flow diagram illustrating a method of indicating decision toselectively offload IP media session to a GAN cell, according to anembodiment of the present invention.

Referring to FIG. 3 , at step 302, the UE 110 registers for videocall/IP media services and also indicates selective IP media sessionoffloading capabilities to the core network 102. At step 304, the corenetwork 102 communicates configuration information associated withoffloading IP media session(s) based on the selective IP media sessionoffloading capabilities. At step 306, the UE 110 detects a GAN cell 108and registers for IP media service only with the GAN cell 108 if thevideo call and IP media sessions are ongoing simultaneously via theGERAN/UTRAN cell 106.

At step 308, the UE 110, upon successful registration, indicatesavailability of the GAN cell 108 for offloading IP media session datastreams to the core network 102. The IP media offloading decisions areconveyed between the core network 102 and the UE 110 and vice versausing a new NAS level signaling message. Accordingly, at step 310, thecore network 102 initiates offloading of the IP media session(s) on tothe GAN cell 108 from the GERAN/UTRAN cell 106. At step 312, the UE 110initiates a transport control connection with the GAN cell 108. At step314, the GAN cell acknowledges to the TC connection message. Finally, atstep 316, the UE 110 initiates a data transfer associated with the IPmedia session(s) with the core network 102 via the GAN cell 108 (e.g.,by sending Unlicensed Mobile Access (UMA) Radio Link Control (URLC)UNITDATA (URLC_UNITDATA)). This data transfer continues over the GANcell 108 until the UE 110 terminates the session or the next sessionstarts.

Various devices, modules, selectors, estimators, and the like describedherein may be enabled and operated using hardware circuitry, forexample, complementary metal oxide semiconductor based logic circuitry,firmware, software and/or any combination of hardware, firmware, and/orsoftware embodied in a machine readable medium may be utilized inaccordance with embodiments of the present invention. For example, thevarious electrical structure and methods may be embodied usingtransistors, logic gates, and electrical circuits, such as applicationspecific integrated circuit may be utilized in accordance withembodiments of the present invention.

While the present invention has been shown and described with referenceto certain embodiments thereof, it will be understood by those skilledin the art that various changes in form and details may be made thereinwithout departing from the spirit and scope of the present invention asdefined by the appended claims and their equivalents.

What is claimed is:
 1. A method of a network entity of a first cell in acommunication system, the method comprising: establishing a firstconnection with a user equipment (UE) using a first access technology;receiving, from the UE, via the first connection, capability informationon communication with a second cell using a second access technology,wherein the second access technology is different from the first accesstechnology; transmitting a first signal to the UE via the firstconnection; and transmitting, to the UE, via the first connection,configuration information related to the second cell, wherein the firstsignal is transmitted to the UE via the first connection while the UEreceives a second signal, from the second cell, via a second connectionbetween the UE and the second cell, and wherein the second connection isestablished between the UE and the second cell using the second accesstechnology based on the configuration information.
 2. The method ofclaim 1, wherein the capability information indicates that the UEsupports an operation to receive signals from the first cell and thesecond cell.
 3. A network entity of a first cell in a communicationsystem, the network entity comprising: a memory; and at least oneprocessor coupled to the memory, wherein the at least one processor isconfigured to: establish a first connection with a user equipment (UE)using a first access technology, receive, from the UE, via the firstconnection, capability information on communication with a second cellusing a second access technology, wherein the second access technologyis different from the first access technology, transmit, to the UE, viathe first connection, a first signal, and transmit, to the UE, via thefirst connection, configuration information related to the second cell,wherein the first signal is transmitted to the UE via the firstconnection while the UE receives a second signal, from the second cell,via a second connection, between the UE and the second cell, and whereinthe second connection is established between the UE and the second cellusing the second access technology based on the configurationinformation.
 4. The network entity of claim 3, wherein the capabilityinformation indicates that the UE supports an operation to receivesignals from the first cell and the second cell.
 5. The network entityof claim 3, wherein the first cell and the second cell are active forthe UE.
 6. A method of a user equipment (UE) in a communication system,the method comprising: establishing a first connection with a first cellusing a first access technology; transmitting, to the first cell, viathe first connection, capability information on communication with asecond cell using a second access technology, wherein the second accesstechnology is different from the first access technology; receiving afirst signal from the first cell via the first connection; receivingconfiguration information related to the second cell from the first cellvia the first connection; establishing a second connection with thesecond cell using the second access technology based on theconfiguration information; and receiving a second signal, from thesecond cell, via the second connection, while the first signal isreceived from the first cell.
 7. The method of claim 6, wherein thecapability information indicates that the UE supports an operation toreceive signals from the first cell and the second cell.
 8. The methodof claim 6, wherein the first cell and the second cell are active forthe UE.
 9. A user equipment (UE) in a communication system, the UEcomprising: a memory; and at least one processor coupled to the memory,wherein the at least one processor is configured to: establish a firstconnection with a first cell using a first access technology, transmit,to the first cell, via the first connection, capability information oncommunication with a second cell using a second access technology,wherein the second access technology is different from the first accesstechnology, receive a first signal from the first cell via the firstconnection, receive configuration information related to the second cellfrom the first cell via the first connection, establish a secondconnection with the second cell using the second access technology basedon the configuration information, and receive a second signal, from thesecond cell, via the second connection, while the first signal isreceived from the first cell.
 10. The UE of claim 9, wherein thecapability information indicates that the UE supports an operation toreceive signals from the first cell and the second cell.
 11. The UE ofclaim 9, wherein the first cell and the second cell are active for theUE.
 12. The method of claim 1, wherein the first cell and the secondcell are active for the UE.